The present invention relates generally to a hitch and more specifically to a hitch for multiple implements which can be converted between an endwise transport position and a forward field-working position.
Farm implements have been made wider to take advantage of increased tractor power and to reduce time in the field. Often two or more implements such a grain drills are ganged and pulled in side-by-side relationship forwardly through the field to plant a wide swath. The forward field-working width of the ganged implements is too great to allow convenient transportation over roads or through narrow gates or the like. Therefore during transportation the implements are often disconnected from the gang and hitched one behind the other so they can be towed in a line to reduce the overall transport width to that of a single implement. Such rearrangement of implements is time-consuming and can require the help of more than one person.
Another way to convert the implements from a field-working to a transport position is to allow the implements to remain in a side-by-side relationship and raise them on transport wheels having fore-and-aft axes of rotation so the implements can be towed endwise. For example, when ganged grain drills are to be transported, rear transport wheels are provided to raise the drills off the ground, while front caster wheels located near the hitch or gooseneck of each drill support the front of the drills. Either a separate drawbar for endwise towing is provided near one end of the implements such as shown in U.S. Pat. Nos. 3,913,683 and 3,610,661, or the main hitch connection can be pivoted from a forward field-working position to an end towing position such as shown in U.S. Pat. No. 4,119,329. Some devices presently available allow the hitch to be changed between the field-working and the transport position without disconnecting the towing vehicle.
Several drawbacks exist in the transport systems typical of the prior art. Some are very massive and relatively inflexible, as a result of one or more large beams extending nearly the entire width of the ganged implements to receive the individual implement hitches. Many require the implements to be hinged or otherwise connected at their adjacent ends while in the field-working position thereby reducing the flexibility of the overall gang and resulting in added stresses and uneven planting or soil working in uneven ground. Generally two rear transport wheels are required for each implement in the gang so that the gang can be raised to a uniform height and adequately supported above the ground in the transport position. An individual hydraulic cylinder must be provided for each wheel assembly, or a linkage assembly connected to a cylinder and to a pair of the wheels is necessary. Therefore when several implements are ganged the number of rear transport wheels and the associated number of hydraulic cylinders and linkages significantly add to the complexity, weight and cost of the hitch. In devices such as shown in the aforementioned U.S. Pat. No. 3,610,661 which use a single transport wheel between pairs of implements, a hinge connection is necessary which limits the flexibility of the gang.